The present invention relates to a semiconductor device, a method of manufacturing the same, and a method of controlling a semiconductor device, in particular, a semiconductor device including a photoelectric conversion element such as photodiode, a method of manufacturing the semiconductor device, and a method of controlling the semiconductor device.
An image sensor used for in-car digital cameras particularly digital single-lens reflex cameras is typically manufactured by forming wirings, applying glass coating to the wirings, and then forming a color-separation color filter and a light-collecting on-chip lens on the glass coating. A reflected light from a photographing object passes through color filters of respective colors, depending on the color of the photographing object and this light travels in a photoelectric conversion element. The light is then converted into charges by photoelectric conversion. By analyzing the amount of these charges, the color of the photographing object is detected.
A color filter is made of an organic material rich in metal so that the color filter cannot be manufactured in a silicon process line. A wafer is transferred to an outsourcing company after the silicon process and there, a color filter is manufactured. This increases the tact time of the product and raises a cost.
In addition to the above-mentioned problem, the organic material serving as a raw material of the color filter changes in quality under a high-temperature environment. An image-sensor using a color filter is therefore not suited for use in, for example, an in-car digital camera. This is because the temperature of, for example, an engine room of a car increases even to 125° C. while the car runs. Further, when an incident light passes through the color filter, its intensity is attenuated by about 30% or more but 50% or less.
For example, the following patent documents disclose a method of analyzing the light quantity for each color of a light, that is, for each wavelength of a light in order to overcome the above-mentioned problems.